1. Technical Field
The present invention relates to a fuse unit connected to, for example, a battery, for supplying electric power to each electric wire through a plurality of fusible portions, and also relates to a method of manufacturing such a fuse unit.
2. Related Art
FIG. 17 illustrates the configuration of a related fuse unit.
A fuse unit 91 connects a battery 89 of a vehicle to electric wires 75 and 76 for supplying electric power. The fuse unit 91 comprises a plate-like fuse element 85 including a fusible portion 79 and made of an electrically conductive metal, and a nearly L-shaped insulating resin body 84, in which the fuse element 85 is insert-molded.
The fusible portion 79 is provided at a middle portion of the fuse element 85 and placed in a cavity 78 of the resin body 84 and has a metal chip 77 comprising an alloy of tin and zinc. The fuse unit 91 is formed in such a way as to be bent at right angles from a middle portion thereof. The fusible portion 79 is placed in a horizontal position.
An end portion extending in a horizontal direction of a fuse element 85 is fastened and connected in vertical direction to a stud bolt 81a of a battery terminal 81 together with a first terminal attached wire 90 by tightening a nut 87. A second terminal attached wire 82 is fastened and connected in the horizontal direction (or lateral direction) to the other end portion extending in a vertical direction of the huge element 85 with the stud bolt 86 and the nut 88. The battery terminal 81 has a ring-like portion 81b fastened and connected to a battery post 89a with the bolt 75 and the nut 74.
A method of manufacturing the fuse unit 91 includes the following steps. That is, first, the fuse element 85 is stamped out from an electrically conductive metal plate (not shown) The fuse element 85 is then bent from a middle portion thereof at right angles. Subsequently, the fuse element 85 is set in a resin molding die (not shown). A molten resin material is then injected into the resin molding die, so that the resin body 84 is integrally formed on each of the top and bottom surfaces of the fuse element 85 in such a manner as to be bent nearly like a letter xe2x80x9cLxe2x80x9d. At that time, parts of the resin body 84, which are connected to the terminals 82 and 90 and surround around the fusible portion 79, are cut out, so that the surface of the conductive material of the fuse element 85 is partly exposed.
The related fuse unit 91 and the manufacturing method therefor have drawbacks in that the drawing structure of the resin molding die becomes complicated due to forming of the resin body 84 in such a way as to be nearly L-shaped, and that the manufacturing cost of the fuse unit is high. Moreover, the related fuse unit 91 and the manufacturing method therefor have another drawback in that the entire length Li of the fuse unit 91 is long, and a large space is thus needed when the set number of fusible portions 79 of the fuse element 85 is increased. Especially, in the case that the set number of the fusible portions 79 is large, the fusible portions 79 are disposed on both the horizontal side and the vertical side of the fuse unit 91, which is bent at right angles, so as to prevent an increase in the size of the fuse unit 91. Thus, the related fuse unit 91 and the manufacturing method therefor have other drawbacks in that the structure of the fuse unit and the drawing structure of the resin molding die are complexed still more, that the fuse unit becomes more difficult to form, and that the cost of the fuse unit is much higher. The related fuse unit 91 and the manufacturing method therefor have another drawback in that the position of each of the fusible portions is restricted because the drawing directions corresponding to portions, which are respectively formed in such away as to extend in a horizontal direction and a vertical direction, of the resin body 84 are orthogonal to each other when the resin body 84 is resin-formed into a bent shape. Additionally, the related fuse unit 91 and the manufacturing method therefor have another drawback in that the fusible unit 91 cannot cope with the complexed circuit form of each circuit in a vehicle owing to a limited space in which each of the terminals is connected to the fuse element.
The present invention is accomplished in view of the aforementioned drawbacks. Accordingly, an object of the present invention to provide a fuse unit, which is formed into a bent shape and can simplify the structure of a resin molding die and reduce the cost thereof and prevent an increase in the size thereof and the mounting-side space thereof and easily obtain a bent shape and increase the flexibility of arrangement of fusible portions thereof and cope with the diversification of the circuit form of each circuit in a vehicle, and to a method of manufacturing such a fuse unit.
To achieve the foregoing object, according to the present invention, there is provided a fuse unit including: an electrically conductive fuse element including at least one fusible portion; a hinge portion provided at the electrically conductive fuse element so that the electrically conductive fuse element is separated into a first fuse element and a second fuse element by the hinge portion and is bendable from the hinge portion; a first resin body provided at the first fuse element; and a second resin body provided at the second fuse element.
According to the fuse unit of the present invention, the first and second resin bodies are respectively provided with abutting faces abutted together when the electrically conductive element is bent from the hinge portion.
According to the fuse unit of the present invention, the fuse unit further includes an engaging mechanism for engaging the first and second resin bodies each other when the electrically conductive element is bent from the hinge portion.
According to the fuse unit of the present invention, at least one first terminal is provided at the electrically conductive fuse element through the corresponding fusible portion, at least one connector housing for accommodating the at least one first terminal is provided in at least one of the first and second resin body.
According to the fuse unit of the present invention, a plurality of the terminals are provided in parallel with one another at the first fuse element, a power supply connecting portion is provided at the second fuse element.
According to the fuse unit of the present invention, at least one terminal connecting portion is provided at the second fuse element.
According to the fuse unit of the present invention, the second fuse element is formed of a first fuse plate connected to the hinge portion and a second fuse plate connected to the first fuse plate through one of the fusible portion, one of the at least one terminal connecting portion for a second terminal is provided at the first fuse plate, the power supply connecting portion is provided at the second fuse plate.
According to the fuse unit of the present invention, the second fuse element is narrower than the first fuse element, a third terminal is placed in a side space at a side of the second fuse element and connected to the power supply connecting portion.
According to the fuse unit of the present invention, the first fuse plate is narrower than the first fuse element, the second fuse plate to which the third terminal is connected is placed in a side space at a side of the first fuse plate.
According to the fuse unit of the present invention, the electrically conductive fuse element is divided in a direction perpendicular to a direction in which the hinge portion extends into a first division portion including a part of the first fuse element and a second division portion including the other part of the first fuse element, the first division portion is connected to the second division portion through one of the fusible portions, the first and second division portion are respectively provided with the first terminals and second terminals.
According to the fuse element of the present invention, the first terminal is for connecting an alternator, the second terminal is for connecting a starter motor, a current branched from the first terminal is supplied to an electric connection box through the fusible portion the said first terminal.
According to the fuse unit of the present invention, the third terminals are positioned between the first fuse element and a battery.
To achieve the foregoing object, according to the present invention, there is provided a method of manufacturing a fuse unit comprising the steps of: providing an electrically conductive fuse element including at least one fusible portion; forming a hinge portion at the electrically conductive fuse element for dividing the electrically conductive fuse element into a first fuse element and a second fuse element; and integrally forming an insulating resin material with the first and second fuse elements in a state in which the electrically conductive fuse element is flattened out.
According to the method of manufacturing the fuse unit of the present invention, the insulating resin material is formed with opposite sides of the first and second fuse elements.
According to the method of manufacturing the fuse unit of the present invention, a space, to which the at least one fusible portion is exposed, is formed at the insulating resin material.
According to the method of manufacturing the fuse unit of the present invention, a connector housing for accommodating a terminal connected to one of the at least one fusible portion is formed at the insulating resin material.
According to the method of manufacturing the fuse unit of the present invention, a exposed portion of the second fuse element corresponding to a terminal contact portion is formed at the insulating resin material.